Mad Cow Disease (Bovine Spongiform Encephalopathy) (Variant Creutzfeldt Jakob Disease)

Bovine Spongiform Encephalopathy or Mad Cow Disease, as it is commonly known, is a very rare, slowly progressive, but fatal degenerative disease of the brain caused by a protein called “prion”. In the 1980’s and 90’s cattle were fed feed that contained animal brain and nerve tissue which resulted in some of these cattle being infected. Humans contract the disease primarily by eating infected beef products.

Where does it occur?

The vast majority has occurred in Britain. Isolated cases have occurred in France, Italy, Ireland, Canada, Israel and USA. For an updated list please go to

How is it transmitted?

It is transmitted by eating meat products from cattle infected with the “prion”. One can also transmit illness through tissue and organ transplant from infected patients or medical equipment contaminated with infected tissue.

Is it contagious from person to person?

There is no person to person transmission with casual every day contact; however blood transfusions or organ transplantation from infected individuals can result in infection.

What is the risk for travelers?

The risk is extremely low. The peak incidence of the disease was in the late 90’s. Comprehensive screening and animal food safety procedures are now in place.

How soon after exposure will one develop symptoms?

Symptoms develop anywhere from 18 months to 30 years after exposure.

What are the signs and symptoms?

Symptoms tend to occur years later and are characterized by confusion, forgetfulness, difficulty walking, involuntary movements of extremities, etc. Symptoms invariably progress till individuals are bed bound and death ensues in 5-12 months.

A rapidly developing dementia-like illness should raise suspicion for Mad Cow disease.


Are there any lab tests to diagnose the illness?

Diagnosis is generally made by symptoms and findings on the brain wave test – called an EEG. Brain biopsy can demonstrate abnormal protein in tissue.

Is there any treatment?

No specific treatment is available.

What preventive measures can be taken?

Avoid eating beef products in countries at risk, or at least restrict to muscle protein like steak and avoid hamburger/sausage that can have neural products mixed in.

Similarly sterilize neurosurgical medical instruments and screen blood donors who have lived in endemic countries during periods of disease outbreaks.

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